Airtight bag packer



Nov. 7, 1967 J. F. GREEN AIRTIGHT BAG PACKEH Filed Feb. 21, 1966 1.. flA0 4w United States Patent ABSTRACT OF THE DISCLOSURE There is describeda bag packer using air to fluidize granular or powdered material inwhich the material is discharged upwardly through a nozzle positionedwithin a hopper containing the material, the nozzle propelling thematerial upwardly through a conduit extending vertically and thenbending through 90 and extending horizontally out of the side wall ofthe hopper. The nozzle is made adjustable by having one elementsupported by a flexible membrane which also acts as a diffusing pad.

The membrane is deformed to move the nozzle element and change the sizeof the orifice opening of the nozzle.

This invention relates to bag packers and, more particularly, isconcerned with improvements in apparatus for fluidizing solidparticulate material with air.

Bag packing machines in which granular or powdered solid materials aremixed and transported by air as the .fluidizing agent are well known. Inthe conventional air bag packer, the material is placed in an enclosedhopper. The bottom of the hopper is slanted, and the spout is connectedto the hopper adjacent the lower bottom edge.

The bottom of the hopper is in the form of a porous pad through whichair is directed under pressure. The air mixes with and suspends thesolid material and carries the solid material out through the spout intothe bag.

The problem with such an arrangement is that the hopper must be abovethe level of the spout, which presents a problem where limited head roomis available. Attempts to arrange the discharge point of the pressurizedhopper chamber below the level of the spout have heretofore not been toosuccessful. The discharge from the hopper. and the spout are bothhorizontally positioned. If they are not at the same level, any conduitinterconnecting the discharge nozzle in the spout must have a doublereverse bend. However, any bend which restricts the flow of air resultsin clogging. This is aggravated by the fact that the material mustbelifted from the point of dischargefrom the hopper up to the level of thespout.

The present invention is directed to an improved air bag packer in whichthe point of horizontal discharge from the hopper chamber to thehorizontal spout need not be locatedat the bottom of the hopper but maybe positioned at some intermediate level along the vertical extent ofthe hopper chamber. This permits the hopper chamber to be lowered inrelation to the position of the spout, substantially decreasing theoverall height of the bag packing machine. At the same time, byeliminating any conduit with double bends, the hopper may be positionedimmediately adjacent the filling spout so as to provide a more compactconstruction than heretofore has been achieved.

In brief, the invention is directed to an air bag packer in which ahopper for receiving particulate solid material forms a fully enclosedair chamber. A conduit has a horizontal portion extending through theside wall of the hopper, the outer end of the conduit forming ahorizontal loading spout for receiving a bag. The conduit curvesdownwardly within the hopper chamber to form a vertical section whichterminates in a nozzle adjacent the bottom wall of the chamber. Thenozzle includes two elefi lfidi Patented Nov. 7, 1%67 ments, one elementforming a convexly curving surface of revolution contiguous with theinternal surface of the conduit, while the second element is supportedby the bottom of the chamber and forms a concavely curving surface ofrevolution extending up into the first element to form therewith anannular orifice. The second element is adjustably spaced from the firstelement so as to vary the size of the orifice. Air is admitted into thechamber under pressure. The bottom wall of the chamber is preferably inthe form of a canvas membrane through which the air is directed into thechamber, the second element of the nozzle being secured to the canvasmembrane so that deformation of the membrane causes the movement of thesecond element toward and away from the first element of the nozzle.

For a more complete understanding of the invention, reference should bemade to the accompanying drawing wherein:

FIGURE 1 is a side elevational view of an air bag packer incorporatingthe features of the present invention; and

FIGURE 2 is a partial sectional view of the nozzle construction in thebag packer of FIGURE 1.

Referring to the drawings in detail, the numeral 10 indicates generallythe frame of the bag packer machine. The frame includes four verticalcorner posts, two of which are indicated at 12 and 14. The verticalposts are joined by horizontal frame members such as indicated at 16, 18and 20.

A bag filling spout 22 and lower bag support 24 are rigidly joined by avertical plate 26 which is supported from the frame 10 by a suitableweighing mechanism (not shown). The weighing mechanism is not materialto the present invention and any conventional weighing mechanism, suchas that described in connection with Patent 2,866,484, may be used. Abag when placed on the Spent 22 is clamped in position by clamping pad28 actuated by a hydraulic or other suitable actuating mechanism 30 toprevent the bag from being blown off the spout as it is being filled.

The solid particulate matter, which is to be loaded into bags, is storedin a hopper indicated generally at 32. The hopper is supported by theframe In in any suitable manner with the lower end of the hopperextending down into the frame well below the level of the spout 22. Theupper end of the hopper is provided with a closure mechanism indicatedgenerally at 34 which includes a flap valve by which the top of thehopper can be opened or closed. The flap valve includes a pivoted flapmember 36, shown in its open position, which can be rotated from avertical open position to a horizontal closed position, indicated by thedotted lines, after the hopper is loaded with the material to be packed.With the flap valve closed, the hopper 3-2 forms a substantiallyairtight chamber.

The lower end of the hopper, as best seen in FIGURE 2, is formed with aprojecting flange 38. A bottom plate 40 is removably secured to theflange 38 by screws, such as indicated at 42. Clamped between the bottomplate 40 and the flange 38 is a gasket 44 and a membrane made of acanvas pad or other flexible porous material, indicated at 46. An airinlet 48 is provided in the bottom plate 40 which, as shown in FIGURE 1,is connected by a pipe 50 and a valve 52 to a source of air underpressure. When the valve 52 is open, air enters the chamber formed bythe hopper 32 through the pores of the canvas membrane 46. Air underpressure may be also admitted to the chamber formed by the hopper 32through an upper air inlet 54 through a valve 56.

According to the present invention, the material in the hopper 32 isconveyed to the spout 22 through a conduit 60 which passes horizontallyout through the wall of the hopper 32 in alignment with the spout 22. Asuitable valve 62 is provided in the conduit between the hopper 32 andspout 22 to control the flow of material out through the spout. Theconduit 60 within the hopper 32 is formed in a large radius 90 bend 64into a downwardly extending vertical section 66 which terminatesadjacent the bottom of the hopper chamber in a nozzle assembly indicatedgenerally at 68.

As best seen in FIGURE 2, the nozzle assembly includes an upper nozzleelement 7 ti and a lower nozzle element 72. The upper nozzle element 70provides a convexly curving surface of revolution 74 which is contiguouswith the interior of the vertical section 66 of the conduit 60. Thus theupper element 70 of the nozzle 68 forms a flaring mouth to the conduit60. The lower element 72 of the nozzle has a concave curving surface ofrevolution 76 which projects upwardly from the surface of the canvaspath 46 into the flaring opening formed by the upper nozzle element 70.In this manner, the upper and lower elements of the nozzle combine toform an annular opening or orifice from the interior of the hopper 32into the lower end of the conduit 60.

The shape of the surfaces 74 and 76 are such that the cross-sectionalarea of the opening decreases in going from the chamber into theconduit. Thus a convergent nozzle is formed which imparts an increase invelocity to air as it passes through the nozzle into the conduit.

In order to handle different materials in which the particles vary insize and density, it is necessary to provide a differententranee-to-throat ratio in the nozzle. In the past this has beenaccomplished by selecting different nozzles depending on the material tobe handled. The present arrangement provides an adjustment between theupper and lower nozzle elements such that the entrance-to-throat arearatio can be readily changed. To this end, an adjusting screw 7 8 isthreaded through the bottom plate 40 and presses against the bottom ofthe lower nozzle element 72 and supporting canvas pad 46. By screwingthe adjusting screw 78 in and out, the canvas pad is deformed and thelower nozzle element 72 can be positioned closer to or further away fromthe upper nozzle element 70 to provide a full range ofentrance-to-throat ratios.

From the above description, it will be recognized that an improved airbag packer is provided. The two element nozzle arrangement with theconduit extending upwardly from the bottom of the hopper chamber to anintermediate point on the wall of the hopper where it passes outwardlyin a horizontal direction to the spout, permits a much more compactdesign with greatly lowered overhead requirements than previous designs.The two element nozzle arrangement also provides for adjustment of theentranceto-throat ratio to permit the bag packer to be used with a widerange of different materials. The bag packer may be used with largepelletized materials, for example, by admitting air in through the uppervalve 56 and inlet 54 rather than admitting air through the lower valve52 and inlet 50. In this case, downward movement of the air impingesupon the larger material particles imparting suflicient momentum to movethe mass of material into the orifice of the nozzle and out the conduit.For finely divided material, of course, the air admitted through thelower valve 52 and inlet percolates through the canvas pad and agitatesthe material into a state of suspension so that it can pass through thenozzle and up through the conduit when the valve 62 is open.

What is claimed is:

1. In a bag packer in which solid particulate material is delivered outof a horizontal spout into a bag, the combination comprising a fullyenclosed hopper for receiving the material, a delivery conduit includinga vertical section within the hopper curving into a horizontal sectionextending outwardly through the wall of the hopper, means coupling thehorizontal section to the spout, the lower end of the vertical sectionflaring outwardly adjacent the bottom of the hopper, means for admittingair under pressure into the enclosed hopper including a porous fabricpad across the bottom of the hopper and means for applying air underpressure to the outside of the fabric pad to permit air to diffuse intothe interior of the hopper, means defining a surface of revolutionhaving a base mounted on the pad and having a tapered point projectingtoward the flared lower end of the delivery conduit to form a nozzle,and adjustable means for deforming the pad to move the nozzle formingmeans toward and away from the lower end of the conduit to change thesize of the nozzle orifice.

2. Apparatus for transmitting solid particulate matter by a stream ofair or other gaseous fluid, comprising means forming a fully enclosedchamber, the particulate matter being loaded into the chamber, thechamber having a bottom wall, a conduit extending into the chamber andhaving a vertical portion extending downwardly in the chamber toward thebottom wall, means forming a converging nozzle at the lower end of saidvertical portion of the conduit, said nozzle means including a firstelement forming a convexly curving surface of revolution contiguous withthe internal surface of the conduit and a second element supported bythe chamber forming a concavely curving surface of revolution positionedto extend up into the first element to form an annular orificetherewith, and means for admitting gaseous fluid under pressure into thechamber, the bottom of the chamber including a porous flexible pad, thesecond element of the nozzle being mounted on and supported by the pad,said gaseous fluid being admitted into the chamber through said pad.

References Cited UNITED STATES PATENTS 2,707,132 4/1955 Baresch 302-533,258,041 6/ 1966 Lau 30229 FOREIGN PATENTS 260,677 1/ 1964 AustraliaANDRES NIELSEN, Primary Examiner,

1. IN A BAG PACKER IN WHICH SOLID PARTICULATE MATERIAL IS DELIVERED OUTOF A HORIZONTAL SPOUT INTO A BAG, THE COMBINATION COMPRISING A FULLYENCLOSED HOPPER FOR RECEIVING THE MATERIAL, A DELIVERY CONDUIT INCLUDINGA VERTICAL SECTION WITHIN THE HOPPER CURVING INTO A HORIZONTAL SECTIONEXTENDING OUTWARDLY THROUGH THE WALL OF THE HOPPER, MEANS COUPLING THEHORIZONTAL SECTION TO THE SPOUT, THE LOWER END OF THE VERTICAL SECTIONFLARING OUTWARDLY ADJACENT THE BOTTOM OF THE HOPPER, MEANS FOR ADMITTINGAIR UNDER PRESSURE INTO THE ENCLOSED HOPPER INCLUDING A POROUS FABRICPAD ACROSS THE BOTTOM OF THE HOPPER AND MEANS FOR APPLYING AIR UNDERPRESSURE TO THE OUTSIDE OF THE FABRIC PAD TO PERMIT AIR TO DIFFUSE INTOTHE INTERIOR OF THE HOPPER, MEANS DEFINING A SURFACE OF REVOLUTIONHAVING A BASE MOUNTED ON THE PAD AND HAVING A TAPERED POINT PROJECTINGTOWARD THE FLARED LOWER END OF THE DELIVERY CONDUIT TO FORM A NOZZLE,AND ADJUSTABLE MEANS FOR DEFORMING THE PAD TO MOVE THE NOZZLE FORMINGMEANS TOWARD AND AWAY FROM THE LOWER END OF THE CONDUIT TO CHANGE THESIZE OF THE NOZZLE ORIFICE.